So your increasing tendon stiffness because during ground strike + take off, the tendons must use greater elastic energy due to the much softer surface?. Wouldn’t that actually dampen the tendon contribution to movement because they are having to absorb and release less force/energy?.
Wouldn’t running on grass require less tendon stiffness (grass) to a movement requiring more stiffness (track) allowing for the tendons to adapt to the increasing forces experienced, thus a harder surface would be more beneficial?.
I know Asafa does a lot of his training on grass back home, not sure about Bolt, as I’ve only seem him training on the track.